55 research outputs found

    Retained Subintimal Pellet in a Carotid Artery

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    A shotgun pellet is depicted in the present image in a carotid artery under the intima, which remained intact without local complications for up to six months. There is lack of data regarding the natural history of such a carotid pellet, but the experience from the myocardium is that, in the absence of infection, completely embedded missiles are usually asymptomatic, tolerated well and may be left in place

    International Business Cycle Synchronization since the 1870s: Evidence from a Novel Network Approach

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    In this study, we examine the issue of business cycle synchronization from a historical perspective in 27 developed and developing countries. Based on a novel complex network approach, the Threshold-Minimum Dominating Set (T-MDS), our results reveal heterogeneous patterns of international business cycle synchronization during fundamental globalization periods since the 1870s. In particular, the proposed methodology reveals that worldwide business cycles de-coupled during the Gold Standard, though they were synchronized during the Great Depression. The Bretton Woods era was associated with a lower degree of synchronization as compared to that during the Great Depression, while worldwide business cycle synchronization increased to unprecedented levels during the latest period of floating exchange rates and the Great Recession

    An inverse problem approach to identify the internal force of a mechanosensation process in a cardiac myocyte

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    Mechanosensation and mechanotransduction are fundamental processes in understanding the link between physical stimuli and biological responses which currently still remain not well understood. The precise molecular mechanism involved in stress and strain detection in cells is unclear. Sarcomeres are the contractile machines of a cardiac myocyte and two main sarcomeric components that are directly involved in the sensation and transmission of mechanical stimuli are titin and filaments (thin and thick). Titin is known as the largest protein in biology with a mass of up to 4.2 MDa. Its flexible region (I-band region) may function as a length sensor (ε=l/l0) while its Z-disc domain may be involved in the sensation of tension and stress (σView the MathML source). Filaments act as contractile machineries by converting biochemical signals into mechanical work which in response cells either shorten or relax. Based on these considerations and a qualitative understanding of the maladaptation contribution to the development of heart failure, an inverse problem approach is taken to evaluate the contractile force in a mathematical model that describes mechanosensation in normal heart cells. Different functional forms to describe the contractile force are presented and for each of them we study the computational efficiency and accuracy of two numerical techniques

    Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic

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    This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic

    Elective cancer surgery in COVID-19-free surgical pathways during the SARS-CoV-2 pandemic: An international, multicenter, comparative cohort study

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    PURPOSE As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19–free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19–free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19–free surgical pathways. Patients who underwent surgery within COVID-19–free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19–free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score–matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19–free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION Within available resources, dedicated COVID-19–free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

    Elective Cancer Surgery in COVID-19-Free Surgical Pathways During the SARS-CoV-2 Pandemic: An International, Multicenter, Comparative Cohort Study.

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    PURPOSE: As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19-free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS: This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19-free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS: Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19-free surgical pathways. Patients who underwent surgery within COVID-19-free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19-free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score-matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19-free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION: Within available resources, dedicated COVID-19-free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

    El seguro de vida

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    Tesis (Licenciado en Ciencias Jurídicas)Debido a los escasos estudios realizados en nuestro país acerca del tema del Seguro de Vida, y no existiendo un texto que contenga un tratamiento acabado que abarque las distintas materias que conforman dicho tema, es que nos hemos propuesto realizar una investigación dogmática y de claridad conceptual del seguro de vida, tomando en cuenta la legislación nacional y la extranjera a modo de mostrar el desarrollo de la institución jurídica tanto en nuestro país como en el exterior. Para lograr lo anterior, se analizará principalmente la doctrina y legislación española. A lo largo del estudio que presentamos, pretendemos aclarar variados temas de temas de contratación aseguradora que revisten una importancia fundamental para el completo entendimiento del contrato de seguro de vida. Así, en los capítulos venideros se presentarán temas tales como los conceptos legales y doctrinales de seguro de vida, las modalidades de éste, su naturaleza jurídica, la materialización del contrato de seguro de vida a través de la póliza, los efectos que produce, y se dará un tratamiento especial al tema del beneficiario del seguro de vida. Se ha dado un tratamiento más extenso a la persona del beneficiario pues es necesario poner de manifiesto la importancia del mismo pues se trata de una institución clásica, no privativa del contrato de seguro sino incluso de todo el derecho privado cuyo desarrollo dogmático impulsará la evolución de la figura del contrato a favor de un tercero. Asimismo y tratando de seguir el orden en que se presenta el tema del beneficiario en una de nuestras fuentes, es que se ha establecido, en el capítulo referido al beneficiario, un tratamiento del mismo siguiendo un orden cronológico de actos jurídicos que abarcan desde su designación hasta la extinción de su derecho

    Μελέτη μακροικονομικών δικτύων με τη χρήση της θεωρίας των γράφων

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    Many modern economic systems are characterized by an increased degree of complexity. The interacting agents of these systems develop individual emergent and non-linear behaviors that cannot be fully described by econometric techniques. In recent years, due to the fast increase of computational power and the evolution of algorithms, the science of Network Analysis has been integrated in the analysis of such complicated economic systems to complement the use of econometrics. A commonly used technique in the context of Network Analysis is the Minimum Spanning Tree (MST). The MST produces a sub-graph of the initial network in which all the nodes are connected so that no loops exist. However, the MST bears some inherent drawbacks that stem directly from its algorithmic identification process and may render it inappropriate for the study of economics networks. This dissertation aims to pin-point the disadvantages of the MST when used in economics networks and to highlight the advantages of a new optimization technique, called the Threshold-Minimum Dominating Set (T-MDS), as a more appropriate solution. Furthermore, the Threshold Weighted - Minimum Dominating Set (TW-MDS) is introduced, which sustains all the advantages of the T-MDS and, depending on the data set at hand, it may be more suitable for inter-temporal analyses that are performed across time. The superiority of the T-MDS and TW-MDS over the classic MST is initially displayed in this dissertation with appropriate theoretical examples. We then continue by delivering a diverse set of macroeconomic applications: business cycle synchronization, income inequality evolution and core inflation measurement. By doing this we show the suitability of the proposed methodologies in macroeconomic analysis. Thus, this dissertation has twofold contributions to the analysis of Complex Economics Networks: on the theoretical side it advances the relative literature by providing a more appropriate tool than the one used so far, while on the empirical side it delivers new insights from the diverse economic applications of the T-MDS.Πολλά σύγχρονα οικονομικά συστήματα χαρακτηρίζονται από αυξημένο βαθμό πολυπλοκότητας. Οι οντότητες αυτών των συστημάτων αναπτύσσουν διακριτές, αναδυόμενες και μη γραμμικές συμπεριφορές που δεν μπορούν να περιγραφούν πλήρως με οικονομετρικές τεχνικές. Τα τελευταία χρόνια, λόγω της γρήγορης αύξησης της υπολογιστικής ισχύος και της εξέλιξης των αλγορίθμων, η επιστήμη της Ανάλυσης Δικτύων ενσωματώθηκε στην ανάλυση τέτοιων πολύπλοκων οικονομικών συστημάτων, συμπληρώνοντας τη χρήση της οικονομετρίας.Μια κοινώς χρησιμοποιούμενη τεχνική στο πλαίσιο της Ανάλυσης Δικτύων είναι το Minimum Spanning Tree (MST). Το MST παράγει ένα υπο-δίκτυο του αρχικού δικτύου στο οποίο είναι συνδεδεμένοι όλοι οι κόμβοι έτσι ώστε να μην υπάρχουν βρόχοι. Ωστόσο, το MST φέρει κάποια εγγενή μειονεκτήματα που προέρχονται άμεσα από τη διαδικασία αλγοριθμικού προσδιορισμού του και μπορεί να το καταστήσουν ακατάλληλο για τη μελέτη οικονομικών δικτύων. Αυτή η διατριβή αποσκοπεί στο να αναδείξει τα μειονεκτήματα του MST όταν χρησιμοποιείται στα οικονομικά δίκτυα και να επισημάνει τα πλεονεκτήματα μιας νέας τεχνικής βελτιστοποίησης, που ονομάζεται Threshold-Minimum Dominating Set (T-MDS) ως μια καταλληλότερη λύση. Επιπλέον, εισάγεται το Threshold Weighted - Minimum Dominating Set (TW-MDS), το οποίο διατηρεί όλα τα πλεονεκτήματα του T-MDS και, ανάλογα με το δεδομένο σύνολο, μπορεί να είναι πιο κατάλληλο για διαχρονικές αναλύσεις που εκτελούνται στην πάροδο του χρόνου.Η ανωτερότητα των T-MDS και TW-MDS σε σχέση με το κλασικό MST αρχικά επισημαίνεται σε αυτή τη διατριβή με κατάλληλα θεωρητικά παραδείγματα. Στη συνέχεια συνεχίζουμε παρέχοντας ένα ευρύ φάσμα μακροοικονομικών εφαρμογών: τον συγχρονισμό των οικονομικών κύκλων, την εξέλιξη της ανισότητας εισοδήματος και τη μέτρηση του πληθωρισμού πυρήνα. Με αυτόν τον τρόπο τονίζουμε την καταλληλότητα των προτεινόμενων μεθοδολογιών στη μακροοικονομική ανάλυση. Έτσι, αυτή η διατριβή έχει διπλή συμβολή στην ανάλυση των σύνθετων οικονομικών δικτύων: από τη θεωρητική πλευρά επεκτείνει τη σχετική βιβλιογραφία παρέχοντας ένα πιο κατάλληλο εργαλείο από αυτό που χρησιμοποιείται προς το παρόν, ενώ από την εμπειρική πλευρά παρέχει νέα αποτελέσματα από τις διαφορετικές οικονομικές Εφαρμογές του T-MDS
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